CODEWITHSUNDEEP
iosobjective-ccore-data
user1178952
user1178952

Reputation:

Proper way to create predicate for relationship for NSFetchedResultsController

If I have an album to songs one-to-many relationship, what is the proper way to set my fetchedresultscontroller to display songs for a given album?

Is my entity songs and my predicate:

[NSPredicate predicateWithFormat:@"album == %@", albumTitle]

Or is my entity albums with a different predicate that somehow reaches across to songs?

Upvotes: 0

Views: 622

Answers (1)

fphilipe
fphilipe

Reputation: 10054

Assuming that your your song has a property album, which in turn has a property title:

[NSPredicate predicateWithFormat:@"album.title == %@", albumTitle]

or if you want malmo to match Malmö, you'd need:

[NSPredicate predicateWithFormat:@"album.title CONTAINS[cd] %@", albumTitle]

where c denotes case insensitive search and d denotes diacritic insensitive search.

For more information, refer to Predicate Format String Syntax Documentation.

Upvotes: 1

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